This animation shows dramatic changes in Greenland's ice mass from 2003 to 2008. Created with data from NASA's Gravity Recovery and Climate Experiment (GRACE), it reveals how much ice has been lost and gained each year. It provides striking visible evidence that Greenland has been losing large amounts of water into the ocean as surface ice melts and glaciers discharge more ice into the sea.

The animation was created using individual images that show how the average ice mass changes for the month of September, the end of the summer season, have varied each year from September 2003. Purple and blue colors indicate the areas and amount of ice loss, and white and red indicates areas of ice gain. The measurements are calculated in terms of centimeters of equivalent water height change per year.

Since its launch in 2002, GRACE has become a key source of knowledge about global ice mass changes. Studies of Greenland using GRACE and other data indicate that between 2000 and 2008 the Greenland ice sheet lost as much as 1,500 gigatons of mass, equivalent to 0.46 millimeters per year of global sea level rise. A recent study published in the journal Science found that increases in snowfall and refreezing since 1995 kept this figure from being twice as large as it would have been otherwise.

Greenland's ice sheet contains about eight percent of all fresh water on Earth. If the entire ice sheet melted, it would raise sea levels globally by about 7 meters (20 feet).

Launched in 2002, GRACE is a collaborative endeavor involving the Center for Space Research at the University of Texas, Austin; NASA's Jet Propulsion Laboratory, Pasadena, Calif.; the German Space Agency and Germany's National Research Center for Geosciences, Potsdam.